B-4 Notices
B.3 Particulate contamination
Attention: Airborne particulates (including metal flakes or particles) and reactive gases
acting alone or in combination with other environmental factors such as humidity or
temperature might pose a risk to the device that is described in this document. Risks that
are posed by the presen ce of excessive particulate levels or con centrations of harmful
gases include damage that might cause the device to malfunction or cease functioning
altogether. This specification sets forth limits for particulates and gases that are intended
to avoid such damage. The limits must not be viewed or used as definitive limits, because
numerous other factors, such as temperature or moisture content of the air, can influence
the impact of particulates or environmental corrosives and gaseous contaminant transfer.
In the absence of specific limits that are set forth in this document, you must implement
practices that maintain particulate and gas levels that are consistent with the protection of
human health and safety. If IBM determines that the levels of particulates or gases in
your environment have caused damage to the device, IBM may condition provision of
repair or replacement of devices or parts on implementation of appropriate remedial
measures to mitigate such environmental contamination. Implementation of such
remedial measures is a customer responsibility.
Table 5. Limits for particulates and gases
Contaminan
Limits
Particulate
•
The room air must be continuously filtered with 40%
atmospheric dust spot efficien cy (MERV 9) according to
ASHRAE Stand ard 52.2
1
.
•
Air that enters a data center must be filtered to 99.97%
efficiency or greater, using high-efficiency particulate air
(HEPA) filters that meet MIL-STD-282.
•
The deliquescent relative humidity of the particulate
con tamination must be more than 60%
2
.
•
The room must be free of conductive contamination such as
zinc whisker s.
Gaseous
•
Copper: Class G1 as per ANSI/ISA 71.04-1985
•
Silver: Corrosion rate of less than 300 Å in 30 days
ASHRAE 52.2-2008 - Method of Testing General Ventilation Air-Cleaning Devices for
emoval Efficiency by Particle Size
nta: American Society of Heating, Refrigerating
and Air-Conditioning Engineers, Inc.
2
The deliquescent relative humidity of particulate contamination is the relative humidity
at which the dust absorbs enough water to become wet and promote ionic conduction.
3
ANSI/ISA-71.04-1985.
nvironmen tal con ditions for process measurement and control
systems: Airborne contaminants. Instrument So ciety of America, Research Triangle
Park, North Carolina, U.S.A.
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